Fix instance method resolution with abstract accessors and methods

tests/language/abstract_method_test.dart

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file

[regis, 2014/04/08 18:02:11]

2014

[hausner, 2014/04/08 19:47:20]

Oh, it's already 2014? Done.

+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "package:expect/expect.dart";
+
+// Checks that abstract instance methods are correctly resolved.
+
+int get length => throw "error: top-level getter called";
+int set height(x) { throw "error: top-level setter called"; }
+width() { throw "error: top-level function called"; }
+
+class A {
+  int get length;     // Abstract instance getter.
+  int set height(x);  // Abstract instance setter.
+  int width();        // Abstract instance method.
+
+  // Must resolve to non-abstract length getter in subclass.
+  get useLength => length;

[regis, 2014/04/08 18:02:11]

I am not sure I understand the difference your fix makes for this test. This
call to length should resolve to the getter in the subclass, whether you have an
abstract getter in A or not.
Your fix seems to take abstract methods into consideration that were not
considered before.

[hausner, 2014/04/08 19:47:20]

Correct. Before this change. We searched for "length" in the local scope, then
in the scope of class A, and didn't find anything (because abstract methods were
not considered.) Thus, the name "length" resolved to the top-level entity.

With this change, we find the (abstract) getter "length" in class A and thus
generate an instance call to the getter, rather than a static call to the
top-level getter.

+  // Must resolve to non-abstract height setter in subclass.
+  setHeight(x) => height = x;
+  // Must resolve to non-abstract width() method in subclass.
+  useWidth() => width();
+}
+
+class A1 extends A {
+  int length;  // Implies a length getter.
+  int height;  // Implies a height setter.
+  int width() => 345;
+  A1(this.length);
+}
+
+main() {
+  var a = new A1(123);
+  Expect.equals(123, a.useLength);
+  a.setHeight(234);
+  Expect.equals(234, a.height);
+  Expect.equals(345, a.useWidth());
+  print([a.useLength, a.height, a.useWidth()]);
+}
+